A mass of 35kg inside a 15kg wagon is pulled by a man across a sandy beach with a coefficient of .25, if the pulling force is 250N, at an angle 25 degrees above the horizontal, how do you determine the net force?

Question

can you determine the net force, force of friction, net force on the wagon, acceleration of the wagon, and how long it takes the man to pull the wagon 100m if it began at rest?

Adrian Ayala · Accepted Answer

Resolve forces between horizontal and vertical components

Assuming the man is pulling the wagon...

The force of friction can be calculated as
#"Friction"=muN#

Where #mu# is the coefficient of friction which we are given as 0.25 and N is the normal reaction

We can calculate the weight as
#W=mg=50kg times 9.81=490.5N#

The wagon is not moving in the vertical direction so the following must hold:

#"Force". sin 25^0+N = weight#

#250.sin25^0+N=490.5#

So N = 384.8N

Hence friction = #384.8times 0.25=96.2N#

So net force in horizontal direction is:

#"Force".cos25^0-96.2N=130.4N#

Acceleration is given by Newton's 2nd law #F=ma#

#a=F/m=130.4/50=2.61ms^-2#

The time to travel 100m from rest can be found using

#s=ut+1/2at^2#
#u=0, s=100m, a=2.61 ms^-2#
so

#100=1/2times2.61timest^2#

So t=8.75s

Charlotte Aaron · Answer

undefined To determine the net force acting on the system, we need to consider the forces acting horizontally and vertically.

1. Horizontal forces: The horizontal component of the pulling force is given by F_horizontal = F_pull * cos(angle), where angle is the angle above the horizontal.

2. Vertical forces: The vertical component of the pulling force is given by F_vertical = F_pull * sin(angle).

The frictional force opposing the motion can be calculated using the coefficient of friction (μ) and the normal force (the weight of the wagon and the mass inside it). The normal force is equal to the weight of the wagon and the mass inside it, which is (35 kg + 15 kg) * g.

The net force in the horizontal direction is the difference between the horizontal component of the pulling force and the frictional force.

The net force in the vertical direction is the difference between the vertical component of the pulling force and the gravitational force (weight).

So, to determine the net force, you would calculate the horizontal and vertical components of the pulling force, the frictional force, and the gravitational force, and then find the resultant force vector by combining the horizontal and vertical components.